feat(statics): add Boba Network (EVM) with ERC20 token support

[bhavesh-prasad]

Summary

• Add CoinFamily.BOBA and UnderlyingAsset.BOBA to base enums
• Add Boba (chainId: 288) and BobaTestnet network classes in networks.ts
• Add boba (mainnet) and tboba (testnet) coin entries with SUPPORTS_ERC20 feature flag
• Add BobaERC20Token class and bobaErc20/tbobaErc20 factory functions in account.ts
• Configure explorer base URLs in sdk-core environments
• Update expectedColdFeatures test fixture and exclude UnderlyingAsset.BOBA from keychains test

Ticket: CECHO-305

[linear]

CECHO-305 [Tempo][UI] Add memo address support for tempo chain

[mullapudipruthvik]

Code review

Found 1 issue:

Critical (score 95):

1. BobaTestnet class uses mainnet chain ID (288), mainnet explorer URLs, and mainnet-derived operation hash prefixes — all three should differ from the mainnet Boba class. Boba Sepolia testnet chain ID is 28882 (confirmed by the testnet explorer URL added in environments.ts: /evm/28882/). Every other EVM testnet in this file uses a distinct chain ID, testnet explorer URL, and matching hash prefix (see ArbitrumTestnet with 421614, BinanceSmartChainTestnet with 97, etc.). In production, testnet transactions would be routed to the wrong chain and explorer links would show mainnet data. chainId should be 28882, nativeCoinOperationHashPrefix and tokenOperationHashPrefix should be 28882, and explorerUrl/accountExplorerUrl should use the testnet bobascan domain.

BitGoJS/modules/statics/src/networks.ts

Lines 2565 to 2575 in 0f2e49c

	class BobaTestnet extends Testnet implements EthereumNetwork {
	name = 'Boba Testnet';
	family = CoinFamily.BOBAETH;
	explorerUrl = 'https://bobascan.com/blockchain/transactions';
	accountExplorerUrl = 'https://bobascan.com/blockchain';
	chainId = 288;
	nativeCoinOperationHashPrefix = '288';
	tokenOperationHashPrefix = '288';
	}

Checked for: CLAUDE.md compliance, bugs, error handling, security, bot-specific failure modes, database operations, code comment accuracy.

[bhavesh-prasad]

@mullapudipruthvik I have addressed the comments